Games like Starport Delta
Games like Starport Delta include Dyson Sphere Program, Kerbal Space Program, Manor Lords, Planetbase, and Oxygen Not Included. We matched them by the tags players give Starport Delta on Steam (Strategy, Indie, Simulation, Space, and Space Sim): closest matches first, and among equally close ones the better-known games.

Dyson Sphere Program
Shared: Space · Base Building · Simulation

Kerbal Space Program
Shared: Simulation · Space · Space Sim

Manor Lords
Shared: Strategy · Simulation · City Builder

Planetbase
Shared: Strategy · Space · Base Building

Oxygen Not Included
Shared: Base Building · Strategy · Simulation

Kingdoms and Castles
Shared: Strategy · Simulation · City Builder

Cities: Skylines
Shared: Simulation · Strategy · City Builder

Space Haven
Shared: Strategy · Base Building · Space

Prison Architect
Shared: Simulation · Strategy · Base Building

Foundation
Shared: Simulation · Strategy · City Builder

FTL: Faster Than Light
Shared: Strategy · Space · Indie

IXION
Shared: Strategy · Space · City Builder

RimWorld
Shared: Strategy · Base Building · Simulation

Against the Storm
Shared: Strategy · Simulation · Base Building

Spacebase DF-9
Shared: Simulation · Space · Strategy

Space Engineers
Shared: Space · Simulation · Sandbox

Banished
Shared: Strategy · Simulation · Indie

Workers & Resources: Soviet Republic
Shared: Strategy · Simulation · City Builder

Anno 2205™
Shared: Strategy · Simulation · City Builder

Dwarf Fortress
Shared: Strategy · Simulation · Base Building

Stellaris
Shared: Strategy · Space · Simulation

Anno 2070™
Shared: Strategy · Simulation · City Builder

Endzone - A World Apart
Shared: Strategy · Simulation · City Builder

The Crust
Shared: Space · Base Building · Strategy